1. Department of Otorhinolaryngology, Severance Hospiral, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
2. Department of Otorhinolaryngology—Head and Neck Surgery, Gwangmyeong Hospital, Chung-Ang University College of Medicine, Gwangmyeong 14353, Republic of Korea
3. Department of Physical Medicine and Rehabilitation, Hanyang University Medical Center, Seoul 04763, Republic of Korea
4. Department of Otorhinolaryngology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Republic of Korea